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Program za ispit
Dependencies: mbed
Revision 0:ff77d67fd52a, committed 2019-03-29
- Comitter:
- Filip10
- Date:
- Fri Mar 29 18:02:34 2019 +0000
- Commit message:
- .
Changed in this revision
diff -r 000000000000 -r ff77d67fd52a Dht11.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/Dht11.cpp Fri Mar 29 18:02:34 2019 +0000 @@ -0,0 +1,89 @@ +#include "Dht11.h" + +Dht11::Dht11(PinName const &p) : _pin(p) { + // Set creation time so we can make + // sure we pause at least 1 second for + // startup. + _timer.start(); + + _temperature = 0; + _humidity = 0; +} + +int Dht11::read() +{ + // BUFFER TO RECEIVE + uint8_t bits[5]; + uint8_t cnt = 7; + uint8_t idx = 0; + + // EMPTY BUFFER + for (int i=0; i< 5; i++) bits[i] = 0; + + // Verify sensor settled after boot + while(_timer.read_ms() < 1500) {} + _timer.stop(); + + // Notify it we are ready to read + _pin.output(); + _pin = 0; + wait_ms(18); + _pin = 1; + wait_us(40); + _pin.input(); + + // ACKNOWLEDGE or TIMEOUT + unsigned int loopCnt = 10000; + while(_pin == 0) + if (loopCnt-- == 0) return DHTLIB_ERROR_TIMEOUT; + + loopCnt = 10000; + while(_pin == 1) + if (loopCnt-- == 0) return DHTLIB_ERROR_TIMEOUT; + + // READ OUTPUT - 40 BITS => 5 BYTES or TIMEOUT + for (int i=0; i<40; i++) + { + loopCnt = 10000; + while(_pin == 0) + if (loopCnt-- == 0) return DHTLIB_ERROR_TIMEOUT; + + //unsigned long t = micros(); + Timer t; + t. start(); + + loopCnt = 10000; + while(_pin == 1) + if (loopCnt-- == 0) return DHTLIB_ERROR_TIMEOUT; + + if (t.read_us() > 40) bits[idx] |= (1 << cnt); + if (cnt == 0) // next byte? + { + cnt = 7; // restart at MSB + idx++; // next byte! + } + else cnt--; + } + + // WRITE TO RIGHT VARS + // as bits[1] and bits[3] are allways zero they are omitted in formulas. + _humidity = bits[0]; + _temperature = bits[2]; + + uint8_t sum = bits[0] + bits[2]; + + if (bits[4] != sum) return DHTLIB_ERROR_CHECKSUM; + return DHTLIB_OK; +} + +float Dht11::getFahrenheit() { + return((_temperature * 1.8) + 32); +} + +int Dht11::getCelsius() { + return(_temperature); +} + +int Dht11::getHumidity() { + return(_humidity); +}
diff -r 000000000000 -r ff77d67fd52a Dht11.h --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/Dht11.h Fri Mar 29 18:02:34 2019 +0000 @@ -0,0 +1,74 @@ +#ifndef DHT11_H +#define DHT11_H + +#include "mbed.h" + +#define DHTLIB_OK 0 +#define DHTLIB_ERROR_CHECKSUM -1 +#define DHTLIB_ERROR_TIMEOUT -2 + +/** Class for the DHT11 sensor. + * + * Example: + * @code + * #include "mbed.h" + * #include "Dht11.h" + * + * Serial pc(USBTX, USBRX); + * Dht11 sensor(PTD7); + * + * int main() { + * sensor.read() + * pc.printf("T: %f, H: %d\r\n", sensor.getFahrenheit(), sensor.getHumidity()); + * } + * @endcode + */ +class Dht11 +{ +public: + /** Construct the sensor object. + * + * @param pin PinName for the sensor pin. + */ + Dht11(PinName const &p); + + /** Update the humidity and temp from the sensor. + * + * @returns + * 0 on success, otherwise error. + */ + int read(); + + /** Get the temp(f) from the saved object. + * + * @returns + * Fahrenheit float + */ + float getFahrenheit(); + + /** Get the temp(c) from the saved object. + * + * @returns + * Celsius int + */ + int getCelsius(); + + /** Get the humidity from the saved object. + * + * @returns + * Humidity percent int + */ + int getHumidity(); + +private: + /// percentage of humidity + int _humidity; + /// celsius + int _temperature; + /// pin to read the sensor info on + DigitalInOut _pin; + /// times startup (must settle for at least a second) + Timer _timer; +}; + +#endif
diff -r 000000000000 -r ff77d67fd52a mbed.bld --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/mbed.bld Fri Mar 29 18:02:34 2019 +0000 @@ -0,0 +1,1 @@ +https://os.mbed.com/users/mbed_official/code/mbed/builds/e95d10626187 \ No newline at end of file